ROR - gate track or drawer rails?

[Sinik]

Inspired by the many that have gone before me, I’ve taken the plunge and now have a Keter Factor 6x6 plastic shed that’s waiting to be assembled for my backyard observatory. 
 

The intention is to make the roof a roll-off though my current conundrum is whether to use v-groove style gate track or extra long drawer tracks. The benefit of the latter being no extra support frame for the track (seems that the right drawer rails will support much higher loads than the plastic roof).

The significant other says she doesn’t want me to put up a structure extending from the back of the shed that she’s reluctantly permitted (which she already refers to as “the Folly). Her main instructions have been “just don’t stuff it up”.
 

Price wise, here in Australia, both options seem to come in at a similar cost. Would welcome any opinions here - my preference is currently to obtain and use some drawer rails, though main concern is how durable these will likely be - guessing that they will be subjected to dew, dust and the like. Also, if I wanted to automate the roof in the future, would that be easier if using a gate track system?

cheers,

Chris

Edited November 3, 2021 by Sinik

[SiD the Turtle]

Sorry I don't have experience in doing this yet but I did just install a Keter shed myself (not for astro). While strong once the metal frame is in, they are very light. If you used drawer tracks wouldn't you have a weight distribution problem where the weight of the opened roof, however light, tries to pull up the base of the shed opposite? Whereas the support frame's designed to take that weight?

[wimvb]

Drawer tracks are mainly for indoor use. In a humid environment or one with a lot of dust, this can lead to problems in the long run. Gate tracks are designed for outdoor use. A friend of mine is also contemplating the use of drawer tracks for his micro-observatory. But he has ready access to them, so it won't be much of an investment for him.

[Carbon Brush]

My observatory was based around a conventional wooden garden shed, with extra strength. Lots of extra strength is required.
I'm sure your Keter shed won't be any different. Sheds rely on being a closed box to stay rigid.
Remove one side (the roof) and it all becomes very flexible.

The roll off track support was constructed of vertical posts and cross members. Otherwise known as a perectly acceptable pergola😁

I fastened (non swivel) castors to the roof and made a channel on the pergola by using PVC waste pipe sawn in half.
This was my only mistake on construction. Snow and ice can remain in the drain channel long after the sky has cleared.
A structure with inverted V on the runners and grooved wheels would have been better.

After 13 years the drain channel plastic is degrading due to ultraviolet light exposure. Yes we do get some sunshine in England🤣.

Just a few ideas.

David.

[Sinik]

Thanks all for your thoughts - leaning towards gate track (have noticed quite a few around while walking the dog, and certainly look as if they will stand up to the outdoors without issue). As for the pergola, might have to construct it and deal with consequences later…😬

[Carbon Brush]

An additional note.
The nmechansim for an up/over garage door made a really good hands free open/close mechanism. 8ft x 10ft shed (in shed builders measurements. Or about 3M x 2.4M.
No pushing and pulling when cold and tired😄

[Rusted]

I have used heavy duty drawer slides outdoors on my heavy, plywood, dome shutters with success.
Three years and counting without obvious deterioration so far.
I have used the same drawer slides with even larger and much heavier shutters on my latest 4.3m Ø dome.
That said, the movement is minimal at only 50cm extension. So the overhang is tiny compared with a shed roof.

I would not hesitate to use tracks and rollers. Make the roll-off roof, supporting structure into a decorative rose trellis.
Or add any other climbing plant which happily tolerates your local climate.
How your partner learns to tolerate two posts and a trellis is none of my business.   

[GraemeC]

I used 20mm electrical conduit as the rails, with nylon rollers that match the 20mm diameter profile of the rail.  The rails stand up clear of any leaves and the nylon rollers work a treat.  I made simple inserts for the galvanised conduit to join lengths together, and standard conduit connectors would leave a big bump on the outside surface.

Graeme

[adyj1]

53 minutes ago, GraemeC said:

I used 20mm electrical conduit as the rails

 I'm trying to picture it - is that just conduit that extends out of the shed, or conduit on top of a wooden beam? (obviously there has to be a structure at the end of the conduit to support it...) 

Edited February 8, 2022 by adyj1

[GraemeC]

The conduct sits on top of treated 4x2 timber beams.  I have a kiddies treehouse next to the observatory, and the beams also form part of that.  So they’re dual purpose and it isn’t obvious at all that the roof can slide over.  The conduit is fixed down by stainless screws every 2 or 3 ft. The screw holes are slightly chamfered so the screw heads are flush.

[GraemeC]

Just to illustrate….

total of 4x 3m lengths of conduit, and 8 rollers.  There is a strip of damp course covering the top of the beams (between the beam and the conduit) to prevent pooling water.

[Rusted]

Don't forget to install retainers to stop the roof from lifting in gales.

I have now scrapped my drawer slides in favour of inline skate wheels rolling in alloy channel section as a guide rail.
Having sourced cheap alloy sections in a scrap yard made the choice quite economical. Otherwise not at all!

The conduit pipe and rollers is an excellent choice. Having the advantage that it will shed rain off the pipe.
Rather than puddling wintry showers and then freezing solid overnight!

[Domain105]

I was in a similar situation where I did not want the extra construction for the roll off structure as space was limited so went with heavy duty drawer slides. First winter since I built my obsy and the roof still slides very smoothly. I made sure they were not exposed to the elements by keeping them inside the structure. So far they are working well with no stickiness or anything. 6months is not long for the rails so I'll see come a year or two!